Miss Mystery
by kelshmel
Summary: AU. Mabel Pines knew there was only one way to face her past. She must return to Gravity Falls. To that decrepit old shack. And with a certain sinister isosceles demon haunting the town; possessing the body of her twin? This wasn't going to be fun. Or particularly easy.
_A/N: Hello good people of the fanfiction community. About four years ago I wrote fics. but was not too experienced (as a 13 year old as you do) and my fics were ~quite~ the embarrassment. But lately I've had an itch to start writing again, and I hope I do much better this time around. And with encouragement from friend, I decided to explore the fic world once again._

 _Gravity Falls has ended, but I always liked the "Mabel Pines runs the Mystery Shack" au. I also was a huge fan of "Bill is still possessing Dipper" deal, which sadly, was unexplored. And I wanted to try it my way. Despite how dark this fic is going to be—I promise a semi happy ending, as I'm not a fan of taking media and making it a trauma fest like some people do (but hey, I'm not gonna judge though)._

 _Summary: Mabel Pines saw her uncle Stanley Pines die at the hands of Bill Cipher eight years ago. The dream demon, possessing Dipper, took off with her brother's body, and his disappearance resulted in an extensive search that led to the announcement of his accidental death. The real Stanford Pines, having returned from another dimension, goes insane due to Bill before he could reveal any of his secrets. Mabel drifts through the next eight years in a depression. When she turns twenty she realizes she wants to return to the Mystery Shacks and take over where Grunkle Stan left off. She decides to become Miss Mystery, and she doesn't expect Bill to show his loathsome face again, but he is far_ _from done with the Pines._

* * *

Mabel Pines was kinda maybe sorta a basket case.

She sauntered the hallways of Piedmont High in her heels and skirts that usually had remnants of glitter in the fabric that never seemed to come out. Long scarves wrapped around her neck always hid her neck no matter how sweltering it got outside. Her sweaters were somewhat of a school enigma—always knitted with curious characters on the front, like the Sasquatch or Loch Ness monster or something unidentifiable that had dripping fangs and scales. Many of the students wondered how she possibly could have mustered the talent to _knit_ these abominations. But Mabel Pines didn't seem to do much of anything, so they figured these sweaters must be her singular passion, besides the occasional boy who she would give a somewhat lingering look at (and these boys were never enthused about the attention despite that fact that Mabel was quite the looker).

It was her emotionless deposition. Her passionless voice that especially gave them the creeps.

She never gave much effort into anything that wasn't her knitting. Her schoolwork was done quickly and without much effort. When she spoke to her peers, which she rarely went out of her merry way to do, her voice held no excitement nor disdain.

When her teachers asked what she would like to do with her life, she merely shrugged and stared with her bottomless dark eyes at a point over their head.

They knew it was probably due to the accident. Having her uncle lose his mind, and her twin brother vanish into thin air was bound to have lasting effects. And with her parents divorcing to boot! (which, not to be cryptic or anything, was to be expected. Most parents who went through the trauma of a dead child rarely stayed together).

It was all due to that fateful August first that shook Mabel Pines to the bone.

* * *

Twenty.

Mabel had turned twenty.

It all felt so wrong. Which surprised her since she hadn't felt much of anything for about...eight years now? She felt like she hasn't aged at all; that she was still that twelve year old who obsessed over boy bands and pigs. A twelve year old girl who was powerless to save her brother from a billions-of-years-old evil.

She forcefully stuck a fork into the stack of pancakes that was her birthday breakfast at Hofferson's Diner. Her mother sat before her, hands holding her face, elbows propped on the red table, staring wistfully at her surviving child. Mabel felt a pang of sadness. Her mother tried, she really did. But her attempts to shower her daughter in affections did not conceal the bags under her eyes and jarring loss of weight. Losing Dipper and her husband in only a matter of a few months took its tremendous toll and Mabel felt guilty for avoiding her gaze.

"You look so beautiful, and _so_ grown up," her mother said. She didn't mention Dipper, or how proud he would be. It was an unstated rule that he would not be brought up. Ever.

Mabel tried to give a smile. "Thanks."

"You could probably snag cashier boy over there," she went on to say, giving her head a tilt towards the dark-skinned boy working. Her mother was right—he _was_ super cute, but Mabel no longer felt the drive to pursue an "epic romance" like she used to. She didn't really have a drive to do anything but knit and watch Discovery Network shows where men would camp in the brush to find the bigfoot. Speaking of which, if they didn't hurry, she would be missing a re-run of Monsterz in The Deep.

She had endeared herself to those types of shows over the years. She even read books about the unexplained instead of young adult supernatural romances (though to be honest, she would never turn down a good vampire make out session). All those nerdy shows and books made her feel closer to _him._

She gave a glance over at the Afro-sporting cashier and giggled half-heartedly. "He is cute."

Her mother smiled, and gave her a hopeful nudge. Mabel sighed. "But if I don't get home in the next thirty-two minutes and five seconds I'll miss my show. It's the episode where they look for the fish with the lizard heads in the Nile."

Her mother deflated. Mabel muttered something about needing to use the restroom and slipped out of the booth. She heard a young girl singing at the karaoke booth at the front in a screechy voice:

 _Everyone was ninja-fighting..._

 _Those hits were quick as lightning..._

 _Therefore it was kind of frightening..._

She remembered the days when she sang at the top of her pubescent lungs with unashamed excitement. Oh, the days. She entered the bathroom and stared at her reflection.

Her sweater was kind of rumpled (she had slept in it last night). A pair of thick black frames sat over her eyes. It was about eight grade when her eyesight began to worsen. She had been warned. Her father was pretty much blind without his glasses-he was a Pines man after all. Her hair had been cropped short sophomore year but had now grown out a considerable length. _I have to cut it again_ , she thought with distaste, _these curls are driving me nuts..._

She exited the bathroom, and what was on the television immediately caught her eye.

Something had happened.

In Gravity Falls.

The tent of telepathy had been put back up. Was Gideon...?

But it wasn't Gideon. Another face, the once of a young woman, came into view. Mabel sighed in relief. Someone must have decided a tent of telepathy was a good idea and resurrected it. But there was no Mystery Shack to combat it.

Her and her mom exited the diner and hopped in the car. The ex Mrs. Pines looked nervous and kept biting her lip. "Mabel...," she began.

"Yes?" she answered tentatively.

"I think...it would be a good choice...no, a great one...ifyouwenttocollege!"

Mabel stopped. Her senior year she had made her choice clear. College was no dice for her. She would probably just fail, having no incentive whatsoever. Her mother had complied reluctantly, for she had not wanted her living child to resent her. She had walked on egg shells around Mabel for years.

"Mom, I told you no two years ago."

"But isn't there something you would like to do? I know you love knitting; maybe you could pursue becoming a fashion designer! Or a photographer! You could help shoot those shows you like so well. I just want you to have a career."

Mabel sighed. Contrary popular belief, she had a job. Granted she was a barista at Starducks, who often made mocha's for the high school peers dropping in for a drink before college classes or their job shift. But still!

She didn't want to do any of those things her peers did. She wanted to fights gnomes, zombies, and gremoblins. She wanted to take pictures of the gobberwonker, uncover conspiracies, and defeat the triangular monster who had stolen her brother.

She wanted to go back in time.

As she thought, her mind went back to that rusty old Mystery Shack. To her uncle in his suit and hat as he conned tourists and even locals out of their money, and at night figuring out a way to bring the real Stanford Pines back.

The more she thought, the more she realized.

"Mom, I already know what I want to do."

* * *

 _Well, I hope that wasn't too shabby, for someone who hasn't written fanfiction in like 2 million years. I'm quite nervous to be uploading this. But hey, I'll take a shot. I'm sorry if the prose seems a bit child-like (I'm attempting to capture the feel of the GF universe yet a little more mature? And it's hard). I'm going to try to keep the atmosphere wistful and somewhat dark—like the show. Mabel has obviously got some issues. She's very OOC, trying to be like her brother and all—and she's obviously battling depression. More will be revealed as to why she is this way and what she will become in the future. Favorite or review if you wish. I appreciate it if you took the time to read this! Thank you! I hope you enjoyed._

 _I can't really see Gravity Falls being a topic on any news station outside of the town itself, but it seemed a convenient route to give Mabel a little nudge on the path to realizing her destiny as "Miss Mystery."_

 _The story will also have a great parallel between Stan's efforts to bring Ford back, and Mabel's efforts to find Dipper. And of course, a bunch of Cipher shenanigans._

 _Next chapter we'll see how Ford is doing (spoiler alert: not so great)._

 _Also, give me a shout out if you noticed the How To Train Your Dragon reference!_


End file.
